Sometimes (I am not sure what causes it) switching from a light color scheme to a dark one is not properly reflected on the panel. In the case of Breeze Dark this means that the panel ends up using some light grey color instead of dark grey as it should. The user has to restart plasmashell or log out in order to get the proper color. I believe this is something that has started happening relatively recently.
STEPS TO REPRODUCE
I don't know what exactly triggers the bug because it doesn't happen every time.
You can use the following video with respective timestamps to see what the problem is (make sure the youtube playback bar disappears):
The color is updated accurately.
Linux/KDE Plasma: Manjaro
KDE Plasma Version: 5.14.3
KDE Frameworks Version: 5.52.0
Qt Version: 5.11.2
Actually it's probably everything QML that doesn't get updated properly, not just the panel, but I'm not sure.
STEPS TO REPRODUCE:
1. Start the session using a dark color scheme and a color-scheme aware desktop theme (tested with: Adapta Nokto colors and Arc Color & Breeze desktop themes)
2. Switch to a light color scheme (tested with: Breeze)
Outcome - Video 1: https://youtu.be/NdxV_4Ea4jU
Note: attached video shows it's also a bug with the Breeze desktop theme and that Breeze Light behaves fine.
Video 2 shows the same happens when going from light to dark colors: https://youtu.be/egXwb-nalyc
btw, use "plasmashell --replace" instead of killall. It'll save and sync first.
(In reply to David Edmundson from comment #3)
> btw, use "plasmashell --replace" instead of killall. It'll save and sync
Ah, I had a hunch there was a better way of doing that, thanks :)
Git commit 7ca1f01ea91a60b5d88a8e1d8f13ec79c1d2302e by Kai Uwe Broulik.
Committed on 07/02/2019 at 15:37.
Pushed by broulik into branch 'master'.
Do background contrast fallback at runtime
When a theme doesn't supply background contrast values, we take an educated guess based on whether it's a dark or light theme.
We didn't update the values when switching only color schemes at runtime (when theme follows it).
This lead to washed out Plasma popup and panel backgrounds. Instead, compute the fallback value at runtime.
Also, while at it, update complimentary colorscheme as well, which was forgotten here.
Differential Revision: https://phabricator.kde.org/D18487
M +6 -20 src/plasma/private/theme_p.cpp
M +20 -0 src/plasma/theme.cpp